Waffle iron



M. H. GRAHAM Dec. 22, 1953 WAFFLE IRON 2 Sheets-Sheet 1 Filed Dec. 11, 1948 64 /NVE/V7 0R. MAURlCE GRAHAM BY M AI'TDRNEY Dec. 22, 1953 M. H. GRAHAM 2,663,785

WAFFLE IRON Filed Dec. 11, 1948 FIG.4

2 Sheets-Sheet 2 MAURICE H. GRAHAM am; aw

ATTORNEY Patented Dec. 22, 1953 UNITED WAFFLE IRON Maurice H. Graham, Minneapolis, Minn., assignor to Generalv Mills, Inc., a. corporation, of. Delaware ApplicationDccember 11, 1948, Serial No. 64,841

13 Claims. 1

This application relates generally to automatic cookers of the wafile iron type in which the batter or material to be cooked is placed in contact with a heated cooking surface such as a mold or grid. More particularly, the invention relates to the combination of an improved timing device with such a member.

Various automatic timing devices have been proposed for use in combination with a waffle iron or grid type cooker. Most of these devices require the use of a bimetallic thermostatic member. On the other hand, a timer has been proposed for use in a cooker of the toaster type, in. which the timer includes a member of so-called thermomagnetic material. So far as I am aware, however, no one has successfully made use of such thermomagnetic material in timing the operation of a iron or cooking mold of the contact type. By thermomagnetic material is understood a metal which under normal temperature conditions has a relatively high m"netic permeability, but which at a certain cri cal temperature exhibits a sharp decrease in magnetic permeability. Such materials or alloys are well known in themselves.

It is accordingly one object of the present invention to provide an improved cooker of the waffle iron type.

It is another object to provide such. a cooker in, combination with an automatic timer embodying a member of thermomagnetic material.

A further object is the provision of an improved thermomagnetic timing device for use with a heated cooking mold.

Still another object is the provision of a timer in which a plurality of thermornagnetic members of different characteristics are utilized.

A still further object is the provision of a timer in which a plate of thermomasnetic material is in direct contact with one surface of a cooking moid, the material to be cooked being in direct contact with an opposite face of the mold.

miother obiectis the provision of an improved thermomagnetic timer in which the parts are mounted so as to provide a definite impact for actuation of a control switch.

Gther objects and advantages of the invention will be apparent from the following description which certain preferred embodiments of the invention are disclosed.

in the drawings which form a part of this application, and in which like reference characters indicate like parts,

Figure 1 is a perspective view of a wafile iron embodying. details of the invention.

Fig. 2, is apartialsectional view of the line 2. 2 of- Fig. l, with certain portions broken away for clearness.

Fig. 3 is a perspective view of an improved thermomagnetic unit according to the invention.

4 is a partial sectional view on the line 2-; of Fig. 2.

Fig. 5 is a partial perspective showing details of the mounting and support member for the thermomagnetic timing unit.

Fig. 6 is a schematic view showing the circuit connections, according to the invention.

Fig. '7 is a partial sectional view of another embodiment of the invention; and

Fig. 8 is a perspective view of a modified thermomagnetic timing unit as used in the device of Fig. '7.

In general I accomplish the objects of the pres ent invention by the use of a thermomagnetic member mounted in good heat conductive relation with one face of the cooking mold. Preferably, the parts are held in direct contact with each other by suitable resilient means. The 0pposite surface of the mold member is in direct contact with the batter or material to be cooked and the temperature of the thermomagnetic member accordingly corresponds very accurately to the temperature of the surface or" the cooked article.

It has been found that the surface temperature of a waffle or similar article reflects accurately the extent to which the cooking operation has been completed. According to the present insvention, I have been able to utilize the temperature of a thermomagnetic member mounted in the above manner to control the operation of a suitable control switch to terminate the cooking operation after the desired surface temperature of the article has been reached.

The switch construction inciudes a permanent magnet which is mounted with respect to the thermomagnetic member so that these part are capable of movement between a relatively separated position. and a relatively close or adjacent position. Under normal conditions of permeability of the thermomagnetic member, the parts are in their adjacent positions and the switch is closed. When the thermomagnetic member reaches its critical temperature and t are undergoes a substantial loss in permeability, the magnet may be moved to a relatively separated position either under the influence of gravity or by a suitable spring or other tension device. This rel ative movement is utilized, to open a control switch and thereby terminate the cooking operaeoaves ation. The mechanism is so designed that a substantial or" the relative movement may take place before the switch is actuated in order that the parts may build up sufficient momentum to obtain instantaneous and positive operation or" the switch.

A novel construction has also been incorporated to obtain variations in the time of cooking. For this purpose several sections of thermomagnetic material ar utilized, each section being of slightly different composition so that its loss of permeability will take place at a critical temperature different from that of the other sections. The sections are so mounted that any one desired section may be selectively moved into operative position with respect to the cooking member and the magnet. Thus the cooking operation may be terminated at diilerent surface temperatures of the material or at the end of different time intervals.

In Fig. 1 I have shown a perspective view or" a v/aiile iron in which the present invention has been incorporated. i'his waffle iron includes a suitable base or supporting plate iii on which upper and lower molds i2 and E i are suitably mounted. ll/lold it is stationary with respect to base it, whereas mold i2 is movably mounted so that the molds can be separated. A cover it encloses the outer portions of the upper mold l2 while a cylindrical shell is encloses the working parts of the mechanism and the lower mold i l. Cover is pivoted at to supports on the base so that the necessary relative movement of molds l2 and it may be obtained by tilting the cover upwardly. A handle 22 on cover it is used for this purpose.

Carrying handles (it may be provided on base ill. The shell or housing is is further provided with a suitable socket for reception of an appliance plug is by means of which the device is connected to a suitable source of current through electric supply cord 23.

With reference to Fig. 6, the wiring diagram and arrangement of the parts are as follows. The plug 26 may be removably engaged with terminals and 32 in the body of the waille iron. Terminal is connected dir ctly by a wire 38 to one end of the heating element 3d of the upper grid i2. Wire ll! in turn connects the other end of upper heating element E i to one end of the lower heating element 35 for grid i i. The other end of element 35 is connected by wire to one blade it of a control switch it. A contact on blade at normally engages a similar 55 on the other switch blade 52. Blade in turn is connected by wire to the other supply terminal 32. A suitable signal light 55 is connected across wires 32 and 5 in order to give a visual indication whenever the switch is open. The switch, when closed, will eiiectively bypass or shunt light 565, so that the light will be off when heating elements 36 and are energized.

One form of thermomagnetic member for use in operation of switch at is shown in perspective in Fig. 3. This thermomagnetic member, designated generally as 53, inclu es a plurality of plates and lit, each of which is made of thermomagnetic material of a composition slightly different from that of the other plates. lhus, for example, all ofthe plates may be of a nickel steel alloy with plate to having a nickel content of roughly 32.5%, with a nickel content of 34% for plate and a nickel content of 36% for plate. es. Each of theseplates. will accordingly sufier a substantial loss in magnetic permeability at its critical temperature, the critical temperature of plate Gil being somewhat less than that of plate $2 while the critical temperature of plate 8c is slightly greater than of plate 52.

lates 6t, 62, and 34 are united to each other and to extensions 68 and of non-thermomagnetic material by suitable joints such as, for example, by silver soldering. Notches are provided at the edges of these joints and extend inwardly between the respective plates in order to minimize the actual area of the soldered connection and thus cut down the transmission of heat from one plate to the other.

Extensions es and iii increase the effective length of the thermomagnetic member 53 for cooperation with suitable g ides by which the member is to be supported. .xtension may include a manipulating portion "52 at outer end for operation by the user.

[is shown in 5, the member i. from below by a pair plates l'i. of these supporting plates has a pair of angular projections it which engage the lower surface of thermomagnetic member The angular faces of these projections '53 permit the l ngitudinal movement of member without interlocking engagement with the notches in the edges of the member. Projections iii are sufficiently resilient to hold the thermomagnetic member firmly against the lower face of the grid.

Plates i i in turn are supported by posts it which are mounted on a frame member which also serves as a support for the switch. It will be noted from Fig. 4 that the upper and lower molds or grids l2 and id are provided with inwardly offset portions i3 and E5 respectively, adapted to form depressions in -e surface of the finished article such as a wafile. These portions 53 and iii are arranged in any desired pattern. The lower grid, for example, thus broken up by these patterned projections.

Thermomagnetic m mber 58 anplates i i are so located that member 2i; immediately adjacent and preferably in heat conductive contact with an area 82 0 lower grid which is not deformed.

As a result of this juxtaposition of member 53 and the lower surface of mold portion 82, the thermomagnetic member will reflect accurately the temperature conditions of the mold itself. Furthermore, since the upper surface of portion 82 of the mold is in direct contact with the batter or material to be cooked, the portion 82 will in turn accurately reflect the surface temperature of the batter. Thus the temperature of the thermomagnetic member will be closely interrelated with the actual surface temperature of the batter and can thus be utilized to determine the length of the cooking period.

To cooperate with the member 58 of thermomagnetic material and achieve operation or" the switch 45, a small permanent magnet 84 is provided. The use of a magnet made of an aluminum nickel alloy is preferred, since such magnets are not adversely afiected by the heat from the cooking operation in the present application. Here, the magnet is so mounted that it is not subjected to direct temperature of the heating element. Such magnets are well known, and may be obtained currently under the trade name Alnico. The magnet and plate 58 are mounted for relative movement between a relatively adjacent position and a relatively separated position. In the present case this is accomplished antenna.

mmting'rmtgnetittv one horizont'atsupport- 'arni ilZ' One endiofi'arm 953' is: providedzwith a pairor downwardly directed flanges each carried by brackets. Hit on" frame memberiit; Thus arm 92' is pivotallymounted with respect to frame member and'also' with respect to thermomagnetic member 58'.

The other end of supporting arm 82 carries an extension l82 on which a suitable insulating block or member lea is mounted; A rod i iifi mounted on the insulatingblock hi engages a vertical slot I88 in theupwardly extending ii 9 of lower switch blade 52. likewise mounted on supporting frame member 363 by insulating plates Ii which separate the switch blades electrically from each other and from theframe;

Aln adjustingscrew' it? is mounted on hori zontal arm between magnet 3 and pivot This adjusting screw; by engagementw-ith sup-- porting plate limits the downward movement of magnet supporting arm ilfiand thus determines the maximum air gap between the poles 85 and 28 of magnet fi-t'and the plate of thermomagnetic material. This maximum air gap must be small enough so that magnet 84 and arm .92 will again be lifted by magnetic attraction when member cools and regains its normal permeability;

The use of slot i in the switch arm i is permits the magnet 84 arm 92 to drop a given distance after the magnet has been released, before extension H6 is engaged to depress contact 5 3 and open the" switch. Thus the parts, which drop under the influence of gravity, gain suificient momentum for positive and instantaneous opening of the switch contacts;

With the foregoing deszription of the structural features of this embodiment in mind, the operation of the device will now be clear. When the device is to be used for baking waiiies, the parts will initially be cold or at room temperature. Therm'omagnetic member 58 will be adjusted in position by operation of finger piece 2' until the desired index mark I i l, H6, or H8 is in position at the outer edge of easing I 8. These marks. correspond to the individual thermomagnetic plates 68, and 54 so that a short, medium, or long time of. cooking can be obtained by the use of a plate having a relatively lower, medium, or higher critical temperature. more stops lid on the ex -nsion may cooperate with housing IE to assist in location of the member After adjustment of the member 53 so that the desired plate lit, 62', or 64 is in position against the lower surface of grid portion 82 and between that portion and the poles of magnettt, the user will connectthe' electrical sup? cord 23 so current will be. brought to the terminals 3E and'BZ.

If member 58 is set waffles as in 2, plate will be in position against grid portion Since plate 65 is at relativel tow temperature; it will have a high magnetic permeability. Magnet 84 will accordingly be-attracted to plate tit and. this attraction will be suiiicie'nt to overcome the downward influ ence of gravity on themembersa Magnet 84' and supporting; arm 92 will accordingly be in the raised position of Fig. 2, in which further upward movement is limited by engagement of pin 1% with the upper end at slot 568. Either a positive step may be provided to assist inestablishing this Switch blades 52 and. 44" are One or for the production of light 6'; upperlimit; or switch arm 44- may be made sufilcientlyri'gid to resist'further upward movement of switcharm 52 'crfextension i It.

In. this raised or relatively close position, the

i upper faces of poles 86 and 88 of magnet ca lie closely adjacent but. preferably not in direct contact with plate A slight air is preferred in thisposition in order that the magnetic attraction will be strong but. at the same time heat will notbe conducted directly from the plate 6!! to the magnet itself.

Since contacts ill and are in engagement in this position of'the parts, the circuit will be completed sothatelectrical heating elements 3 and. for the respective grids will be energized. At the same time the signal light 55 will be shunted by'wires 42 and and switch 15' so that there will'beno visible signal. As soon as the grids are sufficiently hotv the plate 5i of member 53 will reach its critical temperature and the permeability of plate 59 will. suddenly decrease. The-forces of magnetic attraction will therefore be reduced suiliciently so that the magnet drops under the influence of gravity. ard movement of the magnet and its 5 ppor ng arm will open switch it in the described to break the circuit and thus substantially cleenergize the heating elements. The li ht and its resistance will now be in circuit with the heating elements, so that the light will come on, wh le at the same time the energization of elements and is substantially decreased. The light gives a visual signal that the device is hot enough for the coclz- I ing operation.

.magnetic member is in the form of a At this point the housewife open the wafile iron and place thedesired amount of batter on the lower grid i i. The cover lb upper are then moved to tion for the cooking operation.

The introduction of the cold batter will immediately cool the lower grid and 10 the area 52' adjacent thermcma netic ate The platein turn will be cooled to good heat conductiv 0 between the parts and the absence of any substa tial st "a in these elements. As soon as pl I cools below its critical temperature, ility is sit, stantially restored and i again be attracted so that swittheheating elements ree operation. The light will si nify the start actu cookin cycle wi l einp eratui'e of the batter surface, c, a.lja cent grid area 52, becomes s" Lgh so that plate 3b of thersnon ler 53 reaches its critical the m -net isagain perniit'te t nt drop ping movement will open light, and substantially (is elemets. The change in will signifyto the operator that is finished. In. this the i1 wafile within the molds d E". resist rapid cooling of the pal t5 so will remain in the open pos.

has had time to open the co and remove the'wafile.

the above cooking ci cle can desired, and the adjustment of changed to alter the color product.

In Figs. 7 and 8 an the invention is described in ion the 7 This disk is provided with inserts 2 125, and E28 of thermomagnetic material of different characteristics just as in the case of plates 60, 62, and 64 respectively of the embodiment of Fig. 3. Disk I22 is supported on a vertical shaft I30 which is rotatably mounted in any desired manner in the waflle iron housing. A bevel gear 132 at the lower end of shaft i3l! is engaged by a bevel gear i3 3 on a horizontal shaft E36. Shaft I35 in turn projects beyond the casing of the waffie iron and is provided with an external knob $38 for manipulation by the user. Thus rotation of knob 138 will adjust the position of member I22 through the gears 53d and I32 so that the desired plate portion l2 i, I26, or iZS may be selectively engaged with the area 82 of thelower grid just above magnet 8t. Resilient supports may be provided as in the previous case to increase the effective heat conductive contact between the desired plate portion and grid area 82. Magnet M and its associated switch parts are the same in this embodiment as in the previone case. Thus another structure has been provided in which the advantages of the thermomagnetic timer of the present application in combination with the cooking surface of a waffle iron or similar cooker can be obtained, with a relatively simple adjustment for changing the time and final temperature of the cooking operation.

An important advantage of the present construction is the close heat conductive relationship between the cooking surface 32 and the magnetic member 56 or i 22. No matter what portion of the switch cycle the parts may be in when the housewife desires to use the device, the introduction of the cold batter on lower grid is will cool the thermomagnetic member promptly to close the switch and start the cycle. 7

Thus whether the switch be open or closed at the instant the batter is introduced, the cooking cycle will be started without substantial delay. In the event that the grid has not cooled sufiiciently after the waffle has been removed from a previous cooking cycle, the introduction of the batter for the next cooking operation will produce the necessary cooling effect to reinitiate the cycle. Furthermore, whether batter is introduced or not, the thermomagnetic member will function continuously to hold the grids substantially at the baking temperature while idling, i. e., between periods of actual cooking. in other Words, even without the introduction of cold batter, the mold and thermomagnetic member would ultimately cool sufiiciently to reclcse the switch and repeat the cycle. It is my belief that the thermomag netic switch, during such cycling, holds the grids at a more uniform temperature than one can obtain with a switch of the thermostatic type which is currently used for such cooking devices.

A timing device has accordingly been developed in which there is no critical point at which the batter must be introduced for a particular cooking operation. The use of the batter itself to cooperate directly with the switch and condition it for the next cooking cycle thus simplifies greatly the operation of the device from a technical standpoint and eliminates the need for detailed working instructions which are often ignored by the user, with adverse effect on the finished product. With the present combination of cooker and timer, uniform results may be obtained regardless of variations in operation among difierent users and regardless of difierences in the manner in which any one user operates the device.

The provision of a plurality of thermomagnetic portions of different characteristics and the mounting of such portions so that any one of them may be used selectively in cooperation with a portion of the cooking mold and the magnetic part of the switch makes it possible to vary the cooking results in a desired manner without the use of complicated mechanical features.

Changes and modifications may be made in the specific structure and arrangement of the parts, in the light of the teachings of this application. The present invention is accordingly intended to include all such modifications and improvements as fall within the spirit and scope of the attached claims.

Now, therefore, I claim:

1. An electric timing device for use with a heated cooking member having a heating circuit to be controlled, comprising a plate of thermomagnetic material, means for supporting the plate in heat conductive relation with the cooking member, a magnet, means supporting the magnet and the plate for relative movement toward and away from each other in response to changes in permeability of the plate, a control member operatively associated with the last mentioned supporting means and connected to the heating circuit to control the heated member in response to such relative movement, the plate having a plurality of portions of different composition and different thermomagnetic charac teristics, and being movably mounted for selective location of each portion in operative position with respect to both the heated member and the magnet, and manually operable control means connected to said plate for moving it to the desired selective location.

2. An electric timing device for use with a heated cooking member having a heating circuit to be controlled, comprising a plate of thermomagnetic material, means supporting the plate with one face in direct heat conductive engagement with the member, a magnet, means supporting the magnet with its poles adjacent the opposite face of the plate for relative movement toward and away from the plate in response to changes in permeability of the plate, an electric switch operatively associated with the last mentioned supporting means and connected to the heating circuit to control the heated member in response to such relative movement, the plate having a plurality of portions of different thermomagnetic characteristics and being movably mounted for selective location of each portion in operative position with respect to both the heated member and the magnet, and manually operable control means connected to said plate for moving it to the desired selective location.

3. In a cooking device comprising a cooking member having an area for direct engagement with a material to be cooked, and means for heating the member, the improvement comprising a plate of thermomagnetic material, means mounting the plate with one face in direct heatconductive relation to the cooking member at said area, said plate being spaced from the heat" ing means and therefore primarily responsive only to the temperature of the cooking member and any material thereon rather than to the heating means, a magnet, means supporting the magnet with its pole-pieces adjacent the plate for relative movement from a first relatively close position to a second relatively separated position with respect to the plate in response to ,changes in permeability of the plate corresponding to changes in temperature of -the:material to be cooked, and a control member .operatively connected to the heating means and operatively associated with the supporting means, magnet and plate, said control member energizing heating means when the parts are in the first position and deenergizing the heatingmeansand terminating the cooking operation when the. parts move to the second position.

4. In a cool-ring device comprising a cooking member having a relatively thin portion with one surface for direct engagement with the material to be cooked, and an electrical heating element for the member, the improvement corn prising a plate of thermomagnetic material, means mounting the plate with one yfacein dreot heat conductive relation to :the surface :oi.

said thin portion, said plate being spaced from the heating means and therefore primarily responsive only to the temperature of thecooking member and any material thereon rather than to the heating means, a magnet, means supporting the magnet and plate for movement from a first relatively close position to a second relatively separated. position with respect to the plate in response to changes in permeability of the plate corresponding to changes in temperature .of the material to be cooked, and a control switch connected in circuit with the heating element and operatively associated with the supportingmeans, magnet and plate, said control switch energizing the element when the parts are in thetfirst-position and deenergizing the "element and terminating the cooking operation when the parts move-to the second position.

5. A cook n device having a relatively thin one on race of which is adapted for direct contact with the surface of the material to be cooked, hea g i sane for the grid, said grid having a control "ea on its opposite surface out of direct engagenent with the heating means and a thermonlagnetic timer for controlling the energization of the h ating means, said timer including a plate of thermomagnetic material supported in direct heat conducting engagement ag inst the control of said opposite surface of the grid and thereby directly responsive to the temperature of the grid and material and only indirectiy to the temperature of the heating means, said thermomagnetic member controlling the operation of the timer to deenergiae the heating means and terminate the cooking operation in response to change in permeability of the member when the surface of the material to be cooked reaches a predetermined temperature.

6. A cooking device having a relatively thin grid, one surface of which is adapted for direct contact with the surface of the material to be cooked, heating means for the grid, and a thermomagnetic timer for controlling the energization of the heating means, said timer including a plate of thermomagnetic material supported in direct heat conducting engagement against the opposite surface of the grid and thereby directly responsive to the temperature of the grid and material, said thermomagnetic member controlling the operation of the timer to deenergize the heating means when the surface or the material to be cooked reaches a predetermined temperature, the timer including a plurality of thermomagnetic portions of different composition, and readily movable manually operable means for selective engagement of any desired portion with the grid to var" the surface temperature and consequently the degree of cooking of the particular material.

movable manual or 7. A cooking device accordin to claim 5 in which the difierent portions of therm -.:nagnetic material are mounted in align on a longitudinal member, and said ill for longitudinal sliding move. engagement of the desired po" L10 said member having means reducing l tion of heat longitudinally from of tions to another.

8. A cooking device according to c 'n which the portions of different therzno 1a material lo l. Jed oircuinferentially on a rotatable plate c l dii from the c n er of rotation of the p re device including readily crating means for rotation plate and engagement of a selected portion ah. the grid.

In a cooking appliance having a hea -sci cooking member :iordirct engagement with material'to belie cooked a an electric heatingcircuit for-theanember, tneimprorement comprising a base member below the cooking supporting means exten ing pwardly bases. plate of thermoin gnetic nate ed the above the base,.resilient means Lli upwardlyin direct heat conduct" with the cooking member, a ho arm member between the base and t netic plate, one end of the control at 1 f otallymountecl on the base for'ro rental a pernian control arm space ran said having pole pieces e ending ,upt thermomagnetic plate, the arm being movable from a first-pa the magnet is held by its own attraction tively close to the plate to a second position in which the magnet drops away in response to decrease in permeability of the plate at a predetermined temperature or the cooking I r is supported connected to the heating circuit, and connecting means on the control arm and switch controlling the operation of the switch and heating circuit arorement comprising a base member below the cool;- ing member, supporting means extending up wardly from the base, a plate of the; material mounted on the sup-p0 spaced relation above the base a to, means holding the plate in ducting engagement with the und cooking member, a horizontal controi l"- ber between the base and thermoina one place,

a permanent magnet mounted. on spaced from said axis, the magnet pieces extending upwardly toward the magnetic plate, the magnet control ing movable from a first position in magnet is held by its own attraction relatively close to the plate to a second position in which the magnet drops away from the plate in response to decrease in permeability of the plate at a predetermined temperature of the cooking member, a switch also mounted on the base, and connected to the heating circuit, and connecting means on the control arm and switch controlling the operation of the switch and heating circuit in ac cordance with the relative movement of the control arm and magnet toward and away from the plate, said connecting means opening the switch and terminating the cooking operation in response to movement of the magnet and control arm to second position.

11. In a cooking appliance having a heated cooking member and an electric heating circuit for the member, the improvement comprising a base member below the cooking member, supporting means extending upwardly from the base, a plate of thermomagnetic material mounted on the supporting means in spaced relation above the base, in direct engagement with the cooking member, a horizontal control arm member between the base and thermomagnetic plate, one end of the control arm being pivotally mounted on the base for rotation on a horizontal axis, a permanent magnet mounted on the control arm spaced from said axis, the magnet having pole pieces extending upwardly toward the thermomagnetic plate, a switch also mounted on the base, and connected to the heating circuit, and connecting means on the control arm and switch controlling the operation of the switch and heating circuit in accordance with the relative movement of the control arm and magnet toward and away from the plate, said thermomagnetic plate including a plurality of portions of different composition and diiierent thermomagnetic characteristics, the plate being 9 movable on its supporting means for selective location of the difierent portions above the magnet and in direct engagement with the 'undersurface of the cooking member, and a manual control means connected to the plate for moving said portions to the desired selective locations.

12. A cooking appliance according to claim 9 in which one of said control arms and base members is provided with adjustable stop means engaging the other of said members and limiting downward movement of the control arm member away from the plate.

13. A cooking appliance according to claim 9 in which the connecting means on the control arm and switch includes lost-motion means providing for limited initial downward movement of the magnet and control arm before said arm moves the switch.

MAURICE H. GRAHAM.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,617,360 Woodson Feb. 15, 1927 1,655,852 Adams Jan. 10, 1928 1,675,680 White July 3, 1928 1,870,176 Hodgkins Aug. 2, 1932 1,871,262 Ellingson Aug. 9, 1932 1,985,033 Hudson Dec. 18, 1934 2,070,482 Hawkins Feb. 9, 1937 2,207,871 Myers July 16, 1940 2,214,928 Klapperich Sept. 17, 1940 2,267,387 Winborne Dec. 23, 1941 2,269,162 Newell Jan. 6, 1942 2,437,488 Ulanet Mar. 9, 1948 

